KINGSTON, Jamaica (AP) — A recently arrived mosquito-borne virus that causes an abrupt onset of high fever and intense joint pain is rapidly gaining a foothold in many spots of the Caribbean, health experts said Thursday.

There are currently more than 4,000 confirmed cases of the fast-spreading chikungunya virus in the Caribbean, most of them in the French Caribbean islands of Martinique, Guadeloupe and St. Martin. Another 31,000 suspected cases have been reported across the region of scattered islands.